PeachParts Mercedes-Benz Forum - View Single Post - 1980 300TD -- Glow Plug Relay, really weird

dafman · #9 01-07-2019, 05:21 PM

Thank you guys so much! I want to make a post about this at some point, been busy lately, but I will give a little insight. The car was incredibly maintained. One owner from new to 2012, unknown history from there to 2018, some college kid bought it, then I bought it from him.

The paperwork is insane though, the guy dumped over $30,000 into it in the 1990s to... get this... fully restore it. I'm talking: detailed invoices of every thing done from a repair shop: every panel, every line, suspension, climate control, engine and transmission rebuilds, the whole wazoo. Even got it appraised. I'm utterly astounded by this. Clearly that owner loved this car.

That being said, it is in dire need of normal maintenance. The college kid did literally nothing (which he admitted), which is evident by the metal to metal on the brakes. I'm sure it needs valve adjustment, which I am no stranger to (I have other classic cars). I am so excited to own this car (especially since I got it for next to nothing). I know it's running rough because I suspect the thermostat is bad... it never since I've owned it got to temperature, even after a 30 min drive home with it.

At any rate, I'm still really confused about diagnosing the glow plugs. I got get a few to read, each were between 0.9 and 1.1 ohm, but there are 5 plugs and 2 temp sensors going in, and no clear understanding on which line is which! And with my ohmmeter in number one socket, I can read two different glow plugs, and the socket is 1-8 with #4 socket missing (on purpose, it looks like). The fuse in the relay looks good. The plugs look like they have been in there a looooong time, very crusty. Could really use some help with this, like which number should correspond to each plug. It's also possible I'm doing it right and the infinite readings on the meter are right and the plugs are just toast, but I want to make sure before I buy new ones.

At any rate, I am SO excited to own this, the car is really growing on me. I never thought I would own a Mercedes, haha. I will start a thread with a bunch of pictures and even some of the restoration invoices.

Thank you,

Vincent